This invention relates to snowmobiles of the type having a vehicle body driven by suitable endless track means, the front end of the snowmobile being supported upon a pair of transversely spaced steerable skis each connected to the body by suspension means.
Prior proposed suspension and stabilizing systems for such a pair of front skis for a snowmobile have included the use of leaf springs connected with each ski and a shock absorber associated in various ways with the leaf spring as mentioned in U.S. Pat. No. 3,977,485. Stabilization of such leaf spring suspensions further included the employment of torsion bars as shown in U.S. Pat. Nos. 3,674,103 and 3,835,947. In U.S. Pat. No. 3,674,103 the ends of the torsion bar were loosely connected to the pair of front skis by permitting laterally outwardly extending ends of the torsion bar to move in longitudinal openings provided by straps secured to the top of each ski. In U.S. Pat. No. 3,835,947 the inturned end portions of the torsion bar were connected to the ski by outwardly curved links having their outer ends pivotally connected to the ski for movement about a vertical axis. It has also been known to stabilize the front of a snowmobile by a torsion bar having a lever at each end, and linkage pivotally interconnecting each lever with a nonrotatable and vertically movable housing which supports a strut connected to the ski.
In another prior proposed suspension and steering assembly for a ski of a snowmobile, telescoping strut members connect the ski to the snowmobile, the two strut members being nonrotatably connected and one of the strut members being rotatable about its longitudinal axis to steer the ski, U.S. Pat. No. 3,931,862.
Another proposed strut type suspension system shown in U.S. Pat. No. 3,977,485 provided that the strut member connected to the ski should be rotatably mounted and connected with the steering mechanism. This patent also shows a control or stabilizing arm pivotally connected to the rotatable strut at one end and connected to a structural portion of the snowmobile frame or body at the other end.
Such prior proposed suspension and stabilizing systems for snowmobiles represented improvements in steering and riding characteristics of snowmobiles. The strut type suspension and steering system as shown in U.S. Pat. No. 3,977,485 provides substantially independent action of each suspension means and under some conditions may permit excessive rolling of the vehicle when cornering. Further, a severe shock load on one strut during high speed straight running may adversely affect the control and riding characteristics of the snowmobile.